Die boring machine



4 Sheets-Sheet l i w. N R 0 n A INVENTOR. Jahn C. E wart J. C. EWART-DIE BORING MACHINE April 21, 1953 Filed March 1o, 1950 April 21, 1953 yJ. c. EWART 2,635,488

DIE BRING MACHINE Filed Maron 1o, 195o l4 sheets-sheet 2 Z6 6 5 3 6 ,zFIGA Q 8 4? 216 f 9 'y r 1 m1 9 f6 52.123' fr N9 ff w 55g 54 57 g I I lLA' I A IJ l'. Il `57 50 55 5549 `49 55 53 50 51 52 46 5/ Z Z7 \`7( Z426 INVENTOR. John C.Ewari BYH/wbjaa/ TTORHEYJ.

April 21, 1953 .1. c. EWART DIE BORING MACHINE Filed March 10, 195o' 4Sheets-,Sheet C5 IN V EN TOR.

John C.

' E waz-lf A .Byqnm/ AT ToRNEYs.

April 2l, 1953 J. c. EwART 2,635,488

DIE BORING MACHINE Filed March 10, 1950 4 Sheets-Sheet 4 IN V EN TOR.

46 76 72' John :.Ewm

Bywqvwu ATTORNEYS.

Patented Apr. 21, 1953 DIE BORING MACHINE J ohn C. Ewart, Milwaukee,Wis., assignor to A. 0.

Smith Corporation, Milwaukee, Wis., a corporation of New YorkApplication March 10, 1950, Serial No. 148,789

Claims. (Cl. 77-3) This invention relates to a machine for boring pipeswaging dies and the like.

In swaging pipe from a large diameter to a smaller diameter, for exampleunder the disclosure of U. S. Patent No. 2,247,863, issued to Julius B.Tiedemann on July l, 1941, it is necessary to employ a pair ofcomplementary arcuate dies adapted to rock longitudinally on the pipebeing swaged. Each die is provided with a groove which has a curvedtapered portion, for reducing the diameter of the pipe, and a straightuntapered portion for straightening and sizing the pipe to finaldimensions. The formation of such grooves has heretofore been a veryexpensive procedure, involving lengthy milling and grinding operationsas well as a matching operation to insure identity of form between thegrooves of a particular pair of dies.

The principal object of the present invention is to provide a machinewhich will simultaneously bore arcuate tapered grooves in a pair of pipeswaging dies, thereby eliminating the above mentioned milling, grinding,and matching steps and enabling the grooves to be formed atapproximately ten per cent of the previous cost.

Another object of the invention is to provide a die boring machine whichis readily adjustable for various sizes of dies and which will bore botharcuate tapered grooves and straight untapered grooves.

Another object of the invention is to provide a boring machine whereinthe feed screw for the cutting tool is driven through a universal jointcoupling arrangement which permits the boring bar to be adjusted tovarious oblique and parallel positions for boring different types andsizes of dies.

Another object of the invention is to provide a machine whereby a pairof dies may be bored at the same time and rocked during the boringoperation so as to be substantially tangent to each other at the pointof cutting, insuring accurate matching of the grooves and eliminatingthe necessity of a separate matching operation.

Another object of the invention is to provide a :die boring machinehaving inserts which may be `used to adapt the machine for boringvarious types of dies.

The machine, in general, comprises a boring bar adjustably mountedbetween a pair of rotatable head members, a cutting tool adapted to movealong a feed screw on the boring bar and cut matched grooves in anopposed pair of arcuate pipe swaging dies, and cam mechanisms shaped tomaintain the dies in contiguous relationship at the point oi A cuttingand cause the grooves to curve in general accordance with the curvatureof the die faces. The boring bar may be arranged in either obliquerelation with the axis of rotation of the head members, for cuttingtapered or conical grooves, or in parallel relation therewith forcutting untapered or cylindrical grooves. In a separate embodiment ofthe invention, the cam mechanisms are provided with various insertswhich enable the machine to bore either dies for use in the cold swagingof pipe or dies of different cross-section used in hot pipe swagingoperations.

These and other objects and advantages will be set forth more fully inthe following description of embodiments of the invention illustrated inthe accompanying drawings.

In the drawings:

Figure 1 is a top plan view illustrating the use of the machine inboring a pair of pipe swaging dies;

Fig. 2 is a side elevation of the machine, partly in section;

Fig. 3 is an end elevation, looking toward the left in Fig. 2;

Fig. 4 is a cross section taken along line 4 4 of Fig. 2;

Fig. 5 is a schematic perspective view of the driving elements of themachine;

Fig. 6 is a detail cross-sectional view of one of the heads, showing theuniversal joint type coupling arrangement in the cutting tool feedmechanism;

Fig. '7 is a partial top view illustrating the cams and dies as rockedto their position at the beginning of the boring operation;

Fig. 8 is a schematic cross-sectional view of the working portions of apair of cold swaging dies, illustrating the circular cross section ofthe grooves when the dies are used in a swaging machine;

Fig. 9 is a view, corresponding to Fig. l8, of a pair of hot swagingdies and showing the generally elliptical cross section of the groovesas distinguished from the circular cross section of the grooves of Fig.8;

Fig. l0 corresponds to Fig. 9 and illustrates the dies as rocked apartand the pipe as rotated ninety degrees;

Fig. l1 is a partial view of the cam mechanisms of an embodiment whereinthe machine is adapted with inserts for boring cold swaging dies; and

Fig. 12 is a view corresponding to Fig. 11 and showing the inserts usedfor boring hot swaging dies.

The die boring machine, as illustrated in the 3 drawings, comprises abed I, a pair of heads 2 journalled at opposite ends of the bed I forrotation about a horizontal axis, a cylindrical boring bar 3 pivotallyconnected between the heads 2, and a suitable cutting tool 4 mounted formovement along a longitudinal groove 5 in the boring bar 3. The dies 5,which are cast with grooves 'I in their arcuate front faces, arearranged in opposed relation longitudinally of the boring bar 3 andadjusted so that the cutting tool 4 may operate to simultaneously boreboth of the grooves 'I' to final dimensions. The rear portions of thedies 5 are bolted to the vertical front faces of supporting brackets 8which in turn are bolted to the horizontally disposed U-shaped frames 9of cam mechanisms to be described subsequently.

Each head 2 is constructed with a generally annular base member I and arectangular plate slidably mounted in dovetailed relation with acorresponding recess in the front face of the member I0. In order topermit the boring bar 3 to assume various oblique and parallel positionsas the face plates II are adjusted along the recesses in the basemembers Ill, a pair of bearing lugs I2 is rigidly secured to each faceplate for pivotal engagement with trunnions arranged on the ends of theboring bar 3.

Referring to Fig. 6, each plate I is positioned by means of an adjustingscrew I3 which is mounted in a groove I4 in the base member I0 andcooperates with a nut I5 on the plate to move the plate when the screwI3 is turned by the operator of the machine. Although the presentstructure is adapted primarily for a manual adjustment of the faceplates II and boring bar 3, various mechanisms, for example a star wheelfeed, could be employed to move the plates automatically.

With the above described adjusting arrangement, the boring bar 3 may beplaced either in parallel with the axis of rotation of the heads 2, forboring the straight sizing portions I6 of the die grooves 1, or inoblique relation therewith for boring the tapered and arcuate workingportions I'.' of the grooves 1. Synchronous rotation of the heads 2causes the boring bar 3 to describe, depending on the adjustment of theplates II, a single or double cone, a frustum thereof, or a cylinder.

The groove 5 in the boring bar 3 is positioned, with relation to thedirection of adjustment of the face plates so that the cutting tool 4mounted therein will engage the grooved surfaces of the dies '5 and borethe same as the heads 2 and boring bar 3 rotate during a boringoperation,

The cutting tool 4 is fed slowly along the boring bar 3 by a feed screwI8 which is arranged in the groove 5 in the boring bar 3 for threadedconnection with a nut portion I9 of the cutting tool 4. One end of thefeed screw |8 is journalled in a bearing lug 20 on the boring bar 3, andthe other end is journalled in a corresponding bearing lug 2| andconnected to driving members which, together with the drive for theheads 2, will next be described.

Referring particularly to Fig. 5, the main driving elements of themachine are located in the bed I and preferably include an electricmotor 22 operating through a suitable speed reducer 23 to drive a shaft24. The shaft 24 is arranged longitudinally of the boring bar 3 and isjournalled in a pair of large bearing brackets 25 which are rigidlyanchored in the bed I at opposite ends of the machine.

The drive for the heads 2 includes a pair of spur gears 2G connected atopposite ends of the shaft 24 and operating corresponding idler gears 21and thus large spur gears 2B. The gears 28 are mounted at the outer endsof shafts 29 which are integral with their related heads 2 and arejournalled, respectively, in the upper portions of the bearing brackets25.

One of the shafts 29 is formed with a hollow portion 30 having asufficiently large diameter to prevent interference with the operationof the flexible coupling arrangement for the feed screw I8. The variouspairs of gears 26, 21 and 23 are matched to insure that the heads 2rotate in exact synchronism with each other.

rlhe feed screw I8 is driven through a gear arrangement comprising apair of meshing bevel gears 3|, with a driving gear 3| mounted on theshaft 24, and a shaft 32 having one end connected to the driven bevelgear 3| and the other end connected to a worm 33. The shaft 32 extendstransversely of the machine and is journalled in bearings 34 in the bedI.

Worm 33 coacts with a corresponding worm gear 35 which is connected atone end of a shaft 3S. The shaft 3B extends longitudinally of themachine through one of the bearing brackets 25 to rotate a sprocket 31and thus drive a chain 38 and a driven sprocket 39.

As shown in Figs. 5 and 6, the driven sprocket 39 is mounted on a shaft40 which extends axially of the hollow shaft 29 and is journalled in asuitable bearing portion 4| at the outer end thereof. In order toprovide a flexible coupling arrangement between the shaft 4D and thefeed screw I8, a universal joint 42 is secured to the inner end of theshaft 49 and connected through a stud shaft 43 and a second universaljoint 44 to the end of the feed screw I8 which is supported in thebearing lug 2| as previously described.

The stud shaft 43 is formed with a square outer end 45 for slidabledriving connection with a corresponding female portion 45 of theuniversal joint 42. The end of feed screw I8 extends from the bearing 2|through a slot 4l in the face plate and the center opening of theannular base portion I0 of the head 2. These openings, together with thesliding connection in the universal joint 42, permit the face plate tobe adjusted, by turning the adjusting screw I3, to cause the boring bar3 to assume the various degrees of angularity required for boringdifferent types and sizes of dies.

With the described universal joint arrangement, the cutting tool 4 maybe fed smoothly and uniformly along the boring bar 3 regardless of theangularity thereof. The rate of feed is preferably made very slow inorder to prevent dainage to the cutting tool 4 and possible tearing ofthe metal being bored.

To achieve the desired rate of feed, the reduction gearing is selectedto cause the gears 23 and the sprocket 39 to rotate in the samedirection but at a slightly different angular velocity, for examplefifty and forty-nine revolutions per minute, respectively. These angularvelocities are imparted, through the universal joints and shaftspreviously described, to the boring bar 3 and feed screw I8, with theshaft 49 slipping in the rotating bearing 4| at the rate of onerevolution per minute. This one revolution per minute difference betweenthe two velocities is the speed of rotation of the feed screw I8 withrespect to the boring bar 3 and is a sufficiently low relative speed topermit the desired slow feed.

The cam mechanisms which rock the dies 6 during boring, in order tocause the portions II of the die grooves 1 to be cut to curved form,will next be described. These mechanisms are disposed on opposite sidesof a straight track 48 which is shown in Figs. 4 and 7 as centeredlongitudinally of the machine and securely anchored in the bed I.

Each cam mechanism comprises a horizontally disposed arcuate cam member49 which rests on the bed I for rocking contact with the track 48, a camactuator 50 adapted to move along the outer edge of the cam member 49 torock the same, and a feed screw 5I in threaded engagement with a nutportion 52 of the cam actuator 53. Each feed screw 5I is journalled inbearings at opposite ends of the bed I and coacts with the nut portion52 to move the actuator 50 longitudinally of the track 43.

As best shown in Figs. 4 and '7, each cam actuator 50 is preferablyconstructed with upper and lower horizontal sides 53, a pair of outerroller members 54, and a centrally located inner roller member 55 whichis mounted for engagement with the outer edge of a cam 49. rIhe outerrolls 54 move along the vertical inner surface 5B of an elevated edgeportion 51 of the bed I and serve to positively prevent the actuator 50from moving laterally.

To insure against longitudinal sliding of the cams 49 as the camactuators 59 move along the feed screws 5 I, curved tracks 53 aresecured transversely of the machine at opposite ends of the bed I. Thetracks 58 are engaged by suitable rollers 59 which are mounted at theends of the cams 49.

The cams 49 are thus confined at their inner edges by the track 4B, attheir outer edges by the cam actuators 5B, and at their ends by thecurved tracks 58. Accordingly, the movement of the cam actuators 50along the feed screws 5I imparts an accurately defined positive rockingmotion to the cams 43.

The U-shaped frames 9, which support the brackets 3 and thus the dies 6as previously described, are bolted at their ends to the cams 49 withwhich they are associated. The frames 9 bear on the upper surfaces ofthe elevated edge portions 5l of the bed I. These surfaces, as well asthe surfaces of the bed i on which the cams 49 and cam actuators 59rest, are lubricated to permit smooth movement of the cams 49 and tofacilitate transmission of this movement to the dies 6.

The major portion of each cam i9 is curved so that the cams 49 and dies5 will rock when traversed by the cam actuator 50 and cause the taperedWorking portions il of the die grooves l to be bored to arcuateconformation. In boring the straight portions I6 of the die grooves l,which serve to size the pipe as it leaves the swaging machine describedin the U. S. Patent No. 2,247,863 previously referred to, it isnecessary that the dies remain stationary. Accordingly, one end 69 ofeach cam 49 is made relatively straight so that there Will be no rockingmovement when the cam actuator 59 moves therealong.

The drive for the cam actuator feed screws 5I includes a worm gear 6Isecured at one end of a shaft 62 in meshing relation with the worm 33previously described. The shaft B2, which runs parallel with the shaft36 through one 0f the bearing brackets 25, operates through a small spurgear 63 and large idler 34 to drive a gear 65 mounted at the end of oneof the feed screws 5l. The other feed screw 5I is then driven, in

synchronism with the rst, `through a pair of sprockets 66 and chain 61.

The gearing used in driving the feed screws 5I is selected so that thecam actuators 50 will be fed at exactly the same rate as-the cuttingtool 4, and in the same direction. In addition, the cutting tool 4 andthe axes of the inner rolls 55 of the cam actuators 50 are initiallypositioned along a line perpendicular to the axis of rotation of theheads 2. The cams 49 will therefore operate to maintain the dies 6 incontiguous relationship at the point where the cutting tool 4 isoperating, causing the cutting tool to concurrentls7 bore the grooves 1in both dies 6 to accurately matched contours.

The operation of the die boring machine is as follows: assume that apair of dies 6 has been bolted to the brackets 8 on the cam frames 9 andadjusted so that there is a slight clearance between the adjacentportions of the dies. The cam actuators 50 and cutting tool 4 are nextpositioned at one end of their courses of operation, for example withthe inner rolls 55 in contact with the straight portions S0 of the cams49. The portions 60 will then be in engagement with the track 48 and thestraight sizing portions IS of the die grooves 'I will be in boringrelation generally parallel to each other.

The operator next adjusts the screws I3 to cause the boring bar 3 toassume a position parallel to or coincident with the axis of rotation ofthe heads 2, with the cutting tool 4 in position to bore the diegrooves 1. The depth of the cut, and thus the diameter of the groovesbored, may be precisely regulated by using marks on the base portionsIIJ of the heads 2 as base points and adjusting the screws I3 until thecorresponding ends of the boring bar 3 are predetermined distances fromsaid base points.

The machine is then set in motion and the sizing portions I6 of the diegrooves 1 are bored to a cylindrical cross-section corresponding to thecylinder described by the boring bar 3 as the heads 2 rotate. Althoughthe cam actuators 50 move, in synchronism with the cutting tool 4,toward the working portions I'I of the dies 6 as the grooves are bored,the portions I6 will not be bored to arcuate form. This is because theends 69 of the cams 49 are shaped, as previously described, to preventrocking movement during this portion of the boring operation.

As soon as the boring of the straight sizing portions I6 of the groovesI is completed, the operator stops the machine and adjusts the boringbar 3 for boring the tapered and arcuate working portions I1 of thegrooves. This adjustment is made by turning the screws I3 until theboring bar 3 assumes an oblique position corresponding to the desiredtaper and until the cutting tool 4 is in boring relation with the groovesurfaces.

In boring the tapers of dies for large pipes, both ends of the boringbar 3 will be on the same side of the axis of rotation of the heads 2and the bar will describe a frustum of a cone as the heads 2 rotate. Forboring smaller dies, one end of the boring bar 3 may be on the axis ofrotation of the heads, so that a cone is described, or the ends may beon opposite sides of the axis and a double cone described.

The machine is then set in operation for the second time, causing thecam actuators 50 and the cutting tool 4 to resume their travel. As thecutting tool 4 is fed toward the unbored portions of the dies 6, it willdescribe circles of vprogressively increasing diameter and the workingportions I1 of the die grooves 1 will be bored to conical or taperedshape.

In addition. the movement of the cam actuators 50 along the curved edgesof the cams 49 will cause the cams 49 to slowly rock along the track 4Band maintain the dies 6 in contiguous relation at the point where thecutting tool 4 is operating. This causes the grooves 1 to bow in generalaccordance with the curvature of the die faces.

The portions of the die grooves 1 are thus bored to the desired curvedand tapered shape. To prepare the machine for boring a second set ofdies, the first set is removed from the machine and the motor 22reversed, causing the cam actuators 50, cams 49 and cutting tool 4 toresume their initial positions.

It may be desirable, for increased production speed, to provide means tomore rapidly return the elements to their initial positions. Forinstance, the shafts 36 and 62 could be connected through suitableclutches to a separate motor and the cam actuators 50 and cutting tool 4returned to their initial positions without the necessity of rotatingthe heads 2.

When used in a pipe swaging machine such as the one described in thepatent previously referred to, the adjacent portions of the dies 6 arepreferably maintained a slight distance from each other. This is bestillustrated in Fig. 8, wherein a pipe 68 being swaged is shown inrelation to a pair of cold swaging dies. To provide for this gap, thedies 6 are held a corresponding distance from each other during theboring operation, so that a cross-section of each of the grooves 1 willbe slightly less than a semicircle.

The dies shown in cross-section in Fig. 8 are the type generally used inthe cold swaging of pipe, and they may be used in the hot swagingthereof. It is preferable, however, that the dies used in hot pipeswagng be shaped to prevent the hot pipe from being marked by the edgesof the grooves 1 as the dies 6 rock against the pipe.

To accomplish this, the dies 6 may be shaped, as shown in exaggeratedform in Fig. 9, so that a cross-section of the arcuate tapered portions|1 of the corresponding grooves 1 is generally elliptical in form, withthe major axis 69 of the ellipse parallel to the faces of the dies. Therst stroke, or rocking, of the dies 6 during the swaging operation willtherefore form the hot pipe 68 to a corresponding ellipticalcross-section.

As the pipe is fed through the swaging Inaehine described in the patentpreviously referred to, it is rotated ninety degrees between eachrocking stroke of the dies 6. The major axis 10 of the pipe will thus berotated ninety degrees from the major axis 69 of the die grooves 1, asshown in Fig. 10. Accordingly, the pipe will not be in engagement withthe edges of the grooves 1 as the second rocking stroke is performed andthere will be no harmful shearing action between these edges and thepipe.

During the second rocking stroke, the pipe is again formed to an ellipsecorresponding to the shape of the grooves 1, which in effect rotates themajor axis 10 of the pipe ninety degrees. Since the process is repeatedfor each rocking stroke, the edges of the grooves 1 never shear againstthe hot pipe and mark the same.

As in the case of cold swaging dies, the straight sizing portions I6 ofthe die grooves 1 of hot swaging dies are cylindrical in cross-section,so that the pipe is made perfectly cylindrical by the time it leaves theswaging machine.

In the embodiment of the invention illustrated in Figs. 11 and 12, thetrack 48 and cams 49 of the die boring machine are provided with insertsso that the machine may be adapted for boring either cold swaging diesor hot swaging dies.

The track inserts comprise a section 1|, used for boring cold swagingdies, and a section 12 for boring dies used in hot swaging operations.The inserts 1| and 12 are arranged, respectively, in end to end relationwith a shortened main track 48 and are bolted to the bed I at the end ofthe machine corresponding to the straight portions I6 of the die grooves1.

The cam inserts comprise a pair of cam edge sections 13 for boring coldswaging dies and a corresponding pair 14 for boring hot swaging dies.The pairs of edge sections are suitably bolted in corresponding indentedportions 15 at the outer edges of the straight ends 60 of the cams 49.

To bore a set of cold swaging dies, the inserts 1| and 13 are used. Thetrack insert 1| is perfectly straight and is made the same width as themain track 48. The cam inserts 1| are shaped the same as thecorresponding portions of the cams described in connection with the rstembodiment of the invention. The movements of the cams and dies, andthus the shape of the die grooves 1, are therefore the same as thatexplained in the description of the first embodiment.

When it is desired to bore a pair of hot swaging dies, the inserts 1Iand 13 are removed from the machine and the inserts 12 and 14 areinserted. The major portion of the track insert 12 is made slightlynarrower than the main track 48, but the inner end 16 of the insert 12is progressively widened and is the same width as the main track 48 atthe point of engagement therewith.

The cam inserts 14 are made complementary to the track insert 12, sothat the cam actuator 50 operates to positively rock the cams along thetrack.

The operation of the machine, when used with the inserts 12 and 14, isthe same as that previously described except that the cams are spreadapart from each other as they rock up the rise at the inner end 16 ofthe track insert 12.

This slight spreading action is transmitted through the frames 9 andbrackets 3 to the dies 6, causing the cutting tool 4 to cut a shorterarc in each die and making the tapered working portions |1 of the diegrooves 1 shallower than the straight sizing portions |6 thereof. Whenthe dies 6 are used in a swaging machine the distance between the diesis the same as the distance therebetween when the straight portions I6are bored. Accordingly, the straight sizing portions I6 of the grooves 1have a circular cross section, when the dies 6 are in a swaging machine,and the tapered portions I1 have the desired generally elliptical crosssection described with relation to Fig. 9.

The apparatus described in connection with the embodiments of theinvention is operable to bore accurately matched grooves in a variety oftypes and sizes of swaging dies, which enables these grooves to beformed at a small fraction of their former cost. Since the life ofswaging dies is limited, and since the grooves are rebored several timesduring the life of a pair of dies, this saving in the cost of grooveformation may result in an appreciable decrease in the cost of pipeproduction.

Although the machine is particularly designed for boring swaging dies,it is operable to bore a variety of objects. Various sizes and shapes ofcams may be used to regulate the rocking motion, and various inserts maybe used in connection with the cams.

Single tapered articles may be bored in the manner described, and doubletapered articles may be bored by reversing the settings of the ends ofthe boring bar 3 as the cutting tool 4 reaches the converging point ofthe tapers.

Various embodiments of the invention may be employed within the scope ofthe accompanying claims.

I claim:

1. In a machine for making tapered or cylindrical bores in dies andshafts and the like, a support with an annular recessed base plateprovided on the inner side of each head, a pair oi spaced headsjournalled in said support, a boring bar pivoted between said heads, asecond plate slidably mounted in the recess of the base plate andconnected to the boring bar, an adjusting screw threaded into a portionof the second plate member to slide said plate in the recess of the baseplate when the screw is turned by the operator to adjust said boring barto various oblique and parallel positions with relation to the axis ofrotation of said head, a cutting tool mounted on said boring bar, a feedscrew disposed longitudinally of said boring bar and threadedly engagedwith said cutting tool, a flexible coupling arrangement connected to oneend of said feed screw, and means to rotate said coupling and heads atdifferent angular velocities and thus cause feeding of said cutting toolalong said boring bar.

2. In a machine for making tapered or cylindrical bores in dies andshafts and the like, a support, a pair of spaced heads journalled insaid support for rotation about a common axis in synchronism with eachother, a boring bar pivoted between said heads, means to adjust saidboring bar to various oblique and parallel positions with relation tothe axis of rotation of said heads, a cutting tool mounted on saidboring bar, a feed screw journalled longitudinally of said boring barand threadedly engaged with said cutting tool, and means including apair of universal joints to rotate said feed screw with respect to saidboring bar to cause feeding of said cutting tool therealong, one of saiduniversal joints comprising a female portion adapted to receive thesquare end of a shaft of the outer portion to provide a slidingconnection in the joint permitting adjustment of the boring bar tovarious degrees of angularity.

3. In a machine for boring arcuate grooves in swaging dies and the like,a support, a boring bar mounted in said support, a cutting tool disposedon said boring bar for cutting engagement with the grooved portion ofthe die to be bored, means to rotate said cutting tool and feed the samealong said boring bar, and a cam mechanism to rock said die inaccordance with the curvature of said grooved portion and in accordancewith the feeding movement of said cutting tool, whereby said cuttingtool is maintained in boring relation with said grooved portion and saidportion bored to arcuate conformation.

4. In a machine for boring matched arcuate grooves in an opposed pair ofpipe swaging dies or the like, a support, a boring bar rotatably mountedin said support, a cutting tool disposed on said boring bar for cuttingengagement with vthe grooved portions of the dies to be bored,

means to rotate said boring bar and said cutting tool and to feed saidcutting tool, an opposed pair of cams shaped in general accordance withthe curvature of said grooved portions and operably connected with saiddies to rock the same, a pair of cam actuators disposed for engagementwith their respective cams, and means to move said actuators insynchronism with the feeding of said cutting tool and thus to rock saidcams and dies and maintain said dies in contiguous relation at the pointof operation of said cutting tool.

5. In a machine for boring arcuate grooves in swaging dies and the like,a support, a boring bar mounted in said support, a cutting tool disposedon said boring bar for cutting engagement with the grooved portion ofthe die to be bored, means to rotate said cutting tool and feed the samealong said boring bar, and a cam mechanism to rock said die inaccordance with the curvature of said grooved portion and in accordancewith the feeding movement of said cutting tool, said cam mechanismhaving inserts to provide for the boring of different types of dies.

6. In a machine for making tapered and arcuate bores in swaging dies andthe like, a support, a boring bar mounted in said support, means torotate said boring bar about an axis of rotation oblique to the axis ofsaid boring bar, a cutting tool mounted on said boring bar for cuttingengagement with the die to be bored, means to feed said cutting toolalong said boring bar, and a cam mechanism to relatively rock said dieand said axis of rotation in accordance with the curvature of the grooveto be bored in said die and with the feeding of said cutting tool,whereby said cutting tool is maintained in cutting relation with saiddie and a groove is bored to the desired form.

7. In a machine for making tapered and arcuate bores in pipe swagingdies and the like, a support, a pair of spaced heads journalled in saidsupport and rotated about a common axis in synchronism with each other,a boring bar connected between said heads, means to adjust said boringbar to various oblique and parallel positions with relation to the axisof rotation of said heads, a vcutting tool mounted on said boring barfor cutting engagement with the grooved portion of the die to be bored,means to feed said cutting tool along said boring bar, a cam operativelyconnected with said die and curved in general accordance with thecurvature of said grooved portion, a cam actuator disposed to engagesaid cam, and means to move said actuator in synchronism with thefeeding of said cutting tool and thus to rock said cam and die andmaintain said cutting tool in boring relation with said grooved portion.

8. In a machine for making accurately matched tapered and arcuate boresin an opposed pair of pipe swaging dies or the like, a support, a pairof spaced heads journalled in said support and rotated about a commonaxis, a boring bar connected between said heads, means to adjust saidboring bar to various oblique and parallel positions with relation tothe axis of rotation of said heads, a cutting tool disposed on saidboring bar for engagement with the grooved portions of the dies to bebored, I neans including a feed screw and a universal joint couplingarrangement to feed said cutting ltool along said boring bar, a pair ofcams shaped 1n general conformity with the curvature of said groovedportions, and means associated with said cams to move said dies inaccordance with 11 the shape of said cams and with the feeding of saidcutting tool and thus to maintain said dies in contiguous relation atthe point of operation of said cutting tool.

9. In a machine for making tapered and arcuate bores in swaging dies andthe like, a support, a boring bar mounted on said support, means torotate said boring bar about an axis of rotation oblique to the axis ofsaid boring bar, a cutting tool mounted on said boring bar for cuttingengagement with the die to be bored, means to feed said cutting toolalong said boring bar, and a cam mechanism to relatively rock said dieand said axis of rotation in accordance with the curvature of the grooveto be bored in said die and with the feeding of said cutting tool, saidcam mechanism having inserts to provide for the boring of differenttypes of dies.

10. In a machine for making accurately matched tapered and arcuategrooves in an opposed pair of pipe swaging dies and the like, a support,a boring bar mounted in said support, means to rotate said boring barabout an axis of rotation oblique to the axis of said boring bar, acutting tool disposed on said boring bar for engagement with the groovedportions of the dies to be bored, means to feed said cutting 12 toolalong said boring bar, a track mounted longitudinally of and beneathsaid boring bar and having a narrow section and a wide section, a pairof opposed arcuate cams operably associated With said dies and disposedto rock on said track, and cam actuator means to rock said cams on saidtrack and maintain said dies in contiguous relation at the point ofoperation of said cutting tool, with the distance between said dies andthus the depth of the grooved portions depending upon the width of saidtrack.

JOHN C. EWART.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 1,295,251 Aab Feb. 25, 1919 1,346,230 Mediavilla et al. July13, 1920 1,452,320 Staernpi Apr. 17, 1923 FOREIGN PATENTS Number CountryDate 15,351 Great Britain July 6, 1906 18,167 Great Britain Dec. l2,1888 765,346 France Mar. 19, 1934

